Dealing with an Ex

Okay so I have this ex boyfriend and I have told him plenty of times to just please leave me alone. (I am a junior highschooler btw) 
But the main is that he and I share mutual friends and whenever I am with them he always seems to magically appear. 
When he comes to talk to them he does this I guess poking thing to me on my side, but it's like a jabbing into my hit in order for me to yelp in pain.
 I have told him to stop, but he continues to do it. My so called friends aren't any help either. I feel like I am alone on this matter because no matter what I say or do he won't just leave me alone. 
He also has begun to call me a bitch which is really getting under my skin. 
Now me and this ex had a particularly shitty relationship and he was a particular shitty boyfriend to me. He also is delusional to all this which makes everything worse. He doesn't believe he does anything wrong either so, I don't have any clue what to do anymore. 
I have now started to think about going to my school counselor to report this as bullying, but I can't say I didn't say some mean things toward him. I called him like trash and an asshole. 
I just really need to rid him of my life and I don't know whether I should stop hanging out with those friends or go to the counselor or to just ignore him. 
Please give advice I am actually so in dire of help.